Black & Tan 332iT

[Bry5on]

Ok, great successes!

1) Last night I loaded karter16's custom binary that logs extra values over CAN. So far it's working great, even with extra data like lambda integrator, and now I can finally stop bothering the D-bus constantly while I'm driving. Thank you! Datalog of a drive here: https://datazap.me/u/bry5on/kartercan-log?log=0&data=23

2) Today I installed v2 of the exhaust brace. I'd noticed around 3300rpm that a bit of vibration was still coming through, so I modified the design to use the non-m e46 exhaust hanger bushings. Mild-but-still-there improvement. I also discovered that the thin brace to the exhaust has cracked. I guess next time I'll try Ti or just design a weld-on bracket.




3) I got to installing the fender brace with these awesome new rivet nuts (definitely recommend). Fitting up:


Rivet nuts installed:


Bolted in:


After installing the brace, I repeated the earlier experiment but as below with the car 1) in the air and 2) lowered straight on the ground. I left the Slon brace installed for the most conservative test. Measuring displacement here I saw .001"


So what's the verdict? A nice improvement again! The front feels in line with the rear now after the recent work I did back there, and so far it's most noticeable on pothole and sharp road impacts. There's less harshness and the steering feels almost a bit lighter. There's yet another step of less vibration in the steering wheel when driving over not-smooth pavement, although not as drastic a change as the Slon brace. I expect that once I get a chance to put the car through its paces, it'll be even more stable and consistent during cornering, putting the suspension to work instead of the chassis.

If you want to order/recreate this on your own car, click this link and get a set for yourself! https://cart.sendcutsend.com/chn7orju3zid The job took about 4 hours and involves removing the bumper, headlights, fenders at the very least. So budget for a full day as I work pretty fast.

[Bry5on]

Good updates with the braces. Out of curiosity, did the front clip have the windshield and lower subframe brace installed?

Good questions, it did not. I wouldn’t expect much of a change from those two though.

I’m planning a modified re-run of this experiment when I pull my fenders off. Basically set the dial indicator up and watch it as I lift the car up and place it back on the ground. We’ll see what happens!

[discoelk]

Good updates with the braces. Out of curiosity, did the front clip have the windshield and lower subframe brace installed?

[Carbonvert]

Alright, here’s a link for those in the US where you can purchase this v-subframe brace directly if you so desire: https://cart.sendcutsend.com/styxqbkx1nth

Reminder, this link is not me selling anything, I make no money on this, and I’m not affiliated with sendcutsend other than really liking their service.

Just stumbled onto this. Thank you for sharing. I'm thinking this will compliment the redish v3 kit being installed right now

[Obioban]

Seems to now be NLA.

Go, team!

... glad to have mine in hand...

[0-60motorsports]

Got some work done on the flight!

Thats awesome! Great work and Thanks.

[Obioban]

lol.

do want.

awesome!

[karter16]

Oh man - that's huge! Well done - very impressive to have figured that out! The E46 is going to be like a platform that's 10 years younger by the time you're done with it!

[Bry5on]

Got some work done on the flight!

[Bry5on]

Thanks to George Hill I believe we’ve found the remaining flexiness in the front suspension. George has an e46 front clip handy (the man has dedication), so during a visit to TX we ran a test yesterday to prove my next hypothesis. With the fender off, we attached a dial indicator as in the image below, measuring longitudinally, then I pushed on the fender mount vertically with about 40lbs by hand. You could see the dial indicator move .002” from this ~40lb push. This is significant because just sitting on the ground, the car sees about 20x that load, meaning it’s displacing about .040” or a full millimeter from just placing the car on the ground. View of what’s behind the right front fender, with dial indicator setup:


So every time your suspension loads/unloads or hits a pothole/bump, this joint is flexing and allowing the strut tower to move up/down out of sync with the car. This will be noticeable in driver feel.

So we took some scans, including of the other side which had a pothole damaged tower, and I’m going to design some gusseting that will live invisibly under the fender to stiffen the front suspension up nicely.

Thanks George!

[m3_tristan]

You can reach out to @limited.slip on instagram if you’d like to pick one up that’s ready to rock! I just don’t have the free time to pack, ship, distribute.

thanks! I just shot him a message.

[Bry5on]

Sorry new to the forum. Are you selling the csl ducting?

You can reach out to @limited.slip on instagram if you’d like to pick one up that’s ready to rock! I just don’t have the free time to pack, ship, distribute.

[Obioban]

Fits great! Rough math says that the 4 cabrio fasteners will see about 60% of the load of the original 8, and this brace will certainly be stiffer inherently. So an upgrade on paper. No real noticeable change, but it's definitely not less stiff. It's getting hard to do the driveway test as the car isn't making much creaking in the door sills unless it's pretty extreme.

Ordered

[m3_tristan]

Another win today.

This evening I decided to install the first version of the v-subframe-brace.

As a recap, the hypothesis is that:
1) The remaining rear bump oscillations I felt after installing the X-brace are related to a lack of fore-aft/bending stiffness
2) The subframe can rock forward aft, sort of 'around' the axle axis, under throttle application, related to subframe mount failure, and the stock v-brace is not enough to constrain this movement
3, unstated so far) The m-clunk is related to 2) and additionally, the subframe floor acts as a bit of a speaker, amplifying the clunk






I wasn't thinking for a bit and ended up installing M6 rivet nuts instead of M8 rivet nuts, probably because I decided to do this on jack stands instead of driving the 2 miles down the street and getting on the lift. At some point I may try to remove the M6 guys and go to M8 as the design intended, but we'll see how we get along for now.

Early days and not a whole lot of seat time but I can say reasonably confidently that the hypothesis has been validated, and this brace mitigates a lot of that flexibility.

Response and oscillations following bumps are much tighter, and throttle applications are more 'instant' and don't have that coil-up feeling that the e46 has. You can be a bit rougher with throttle application and removal and it doesn't feel as rough on the chassis, it just follows your foot.

I've only got a handful of miles on the car, attempting to provoke it of course, but so far I haven't been able to get it to m-clunk. You can for sure get it to cluck by going on/off/on/off throttle very quickly, but this is true even on the newer G80 cars. Shifting feels a little smoother? Not so much in the lever, but in the car itself. Definitely need more miles to validate this.

On top of that, it does seem to be even more torsionally rigid when exiting extreme driveway angles. I can tell again that the front is less rigid than the rear. I wonder if recreating the e30 cabrio front strut mount gusseting would be useful. I'm really going to have to do those control arms and a new set of bushings now.

Anyway, pleased with this! The car has really transformed a generation or two in ride feel in the past few weeks.

Sorry new to the forum. Are you selling the csl ducting?

[Bry5on]

Let us know how it fits! I’m curious why the m3 vert didn’t get it.

Fits great! Rough math says that the 4 cabrio fasteners will see about 60% of the load of the original 8, and this brace will certainly be stiffer inherently. So an upgrade on paper. No real noticeable change, but it's definitely not less stiff. It's getting hard to do the driveway test as the car isn't making much creaking in the door sills unless it's pretty extreme.